Gas Exchange In Insects

Question 1

Adaptations to prevent water loss

Answer 1

1) small sa: volume ratio where water can evaporate from
2) ( lipid layer ) = waterproof exoskeleton
3) spiracles, where gases and water can evaporate from , can open and close to reduce water loss

Question 2

Insect tracheal system

Answer 2

trachea, tracheole and spiracles

Question 3

Describe how the structure of the insect gas exchange system provides cells with sufficient oxygen and limits water loss. (5)

Answer 3

They have spiracles which allows diffusion of O2 through tracheoles. Tracheoles are highly branched so they need a large surface area for gas exchange. The tracheole walls are thin = short difusion pathway and are permeable to o2. However, exoskeleton is impermeable which means it reduces water loss. There are also hairs around the spiraces which also reduce water loss.

Question 4

Methods of moving gases

Answer 4

1) diffusion,